docs: completely overhaul README with comprehensive documentation (JhaSourav07#3425)

## Description
Completely overhauls README with comprehensive documentation including
30+ parameter matrix, theme presets, architecture docs, and self-hosting
guide.

## Changes Made
- Added complete query parameter matrix with 30+ parameters
- Added theme preset table with 11 themes
- Added isometric monolith design philosophy
- Added architecture and tech stack documentation
- Added self-hosting instructions
- Added automated contributor workflow
- Added comprehensive FAQ section

## Pillar
📚 Documentation

## Visual Preview
N/A – Documentation-only change

## Checklist before requesting a review:
- [x] I have read the CONTRIBUTING.md file.
- [x] I have tested these changes locally.
- [x] I have run npm run format and npm run lint locally and resolved
all errors.
- [x] My commits follow the Conventional Commits format.
- [x] I have updated README.md.
- [x] I have started the repo.
- [x] I have made sure that I have only one commit to merge in this PR.
- [x] The SVG output matches the CommitPulse "premium quality" aesthetic
standard.

Fixes JhaSourav07#239

Author: JhaSourav07